1. Field of the Invention
The present invention relates generally to a thin film transistor array panel, and an organic light emitting diode display.
2. Description of the Related Art
An organic light emitting diode display is a self-light emitting display device including an organic light emitting diode for emitting light to display an image. Unlike a liquid crystal display, the organic light emitting diode display does not require a separate light source so that a thickness and weight thereof may be relatively decreased. Furthermore, since the organic light emitting diode display exhibits a high grade characteristic, such as low power consumption, high luminance, and a high response speed, thereby having attracted attention as a next generation display of a portable electronic device.
The organic light emitting diode display is classified into a passive matrix type and an active matrix type according to a driving method. The active matrix-type organic light emitting diode display includes an organic light emitting diode, a thin film transistor (TFT), and a capacitor for each pixel to independently control the pixel.
The organic light emitting diode display has a characteristic in that optical efficiency is lower than that of another display device, such as a CRT, a PDP, and a PED.
This causes a problem in that light emitted from the organic light emitting diode display is totally reflected from an interface between an electrode and a substrate and an interface between the substrate and the air, so that a light extraction ratio deteriorates, and light emitted from the organic light emitting diode display is confined between the electrode, an organic layer, and the substrate, so that the light fails to be emitted to the outside and dissipates.
The above information disclosed in this Background section is only for enhancement of an understanding of the background of the described technology, and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.